Background: Despite growing recognition that patient preferences and values should inform cancer care, patients’ views continue to be under-represented. We developed a quantitative tool, Valued Outcomes in the Cancer Experience (VOICE), to measure patient priorities and to understand discrepancies between what matters most to patients and what patients believe they can control. This study presents VOICE development and initial validation. Methods: 459 cancer patients completed an online survey and rated level of importance and perceived control for 54 value items (0=not at all; 4=very much). Items were derived from patient and caregiver focus groups and included themes such as independence, functional abilities, planning for the future, symptom management, health knowledge, and social support. Participants also completed validated measures of hope, optimism, quality of life, financial toxicity, spiritual well-being, illness perceptions, social support, self-efficacy, intolerance of uncertainty, and cancer-related distress. Iterative exploratory factor analysis (EFA) with direct oblique rotation, magnitude of importance and control ratings, and Pearson correlations between items and validation measures were used to inform scale refinement. Results: Participants were 86% non-Hispanic white; mean age=60 years, SD=10; 38% breast cancer, 18% blood, 9% lung, 9% prostate; mean time since diagnosis=6.5 years, SD=6; 22% metastatic. Items that did not load in the EFA, or were not associated with conceptually relevant validation measures, were removed or reworded. The final EFA explained over half of the variance in the data and demonstrated good fit, with absolute and relative fit indices in established acceptable ranges (P<.001). The refined VOICE measure addresses diverse themes including access to care, maintaining independence, longevity, shared decision making, illness understanding, symptom management, emotional support, connection to illness community, spirituality, and end of life preparation. Conclusions: The study results demonstrate a framework for developing a quantitative, multidimensional measure of patient values. By understanding what matters most to patients, VOICE is positioned to bring patient preferences to the foreground of cancer care, contribute to shared decision making, and enhance care. Next steps include further validation of this tool in diverse settings, including oncology practices and community-based organizations.